One page summary: Hypotonia, or low muscle tone

In two sentences

Hypotonia means low muscle tone. A baby with hypotonia feels floppy when you pick them up, and their limbs offer less resistance than expected when moved. ¹

Hypotonia is a finding, not a diagnosis. It has a long list of possible causes, from brain injury to genetic conditions to problems in the nerves and muscles themselves, and the first job is to work out which group your child is in.

The numbers, with their sources

• Tone is not strength. Tone is the resting resistance in a muscle. Strength is the force it can produce. A child can have low tone and normal strength, or both together ¹
• The main division. Central hypotonia comes from the brain or spinal cord. Peripheral hypotonia comes from the nerves, the junction with the muscle, or the muscle itself ²
• What separates them at the bedside. Central hypotonia usually comes with normal or brisk reflexes and relatively preserved strength. Peripheral hypotonia usually comes with weak or absent reflexes and clear weakness ²
• A common surprise. Many babies who go on to have spastic cerebral palsy are floppy in the first months, with tone increasing later ³
• Why the workup matters. Some peripheral causes are progressive and a few now have specific treatments, so identifying them changes what happens rather than only naming it ¹
• What to do meanwhile. Referral to early intervention does not require a diagnosis and the evaluation is free ⁴

What to do this week

1. Ask whether this looks central or peripheral, and what the reasoning is.
2. Ask what workup is planned, and specifically whether genetic testing is included.
3. Ask whether spinal muscular atrophy has been ruled out, since specific treatment exists.
4. Ask for a feeding and swallow assessment if feeds are slow or your baby coughs.
5. Refer to early intervention today, without waiting for a diagnosis.
6. Ask a therapist to show you how to carry and position your child for the best function.

Questions to take with you

Take these with you. Write the answers down in the moment, because you will not remember them later.

For the pediatrician or neurologist

• Does this look central or peripheral, and what makes you think so?
• What are the reflexes, and is there real weakness as well as floppiness?
• What testing is planned, and what would each test change?
• Has spinal muscular atrophy been excluded?
• Is an MRI indicated?

For the feeding team

• Is my baby swallowing safely?
• How long should a feed take, and what are we aiming for?
• What are the signs that food is going the wrong way?

For the therapy team

• How should I carry and position my child?
• What one goal are we working on now?
• What equipment would help, and when?

You can also build a printable list with the question generator.

Where to read more

The full page on this condition covers how it happens, causes split into what happens even with perfect care and what is associated with gaps in care, signs by age, diagnosis, treatment, outlook, daily life and lifetime cost.

Read the full page on Hypotonia, or low muscle tone

Related pages are listed at the bottom of it, including the events that can lead to this condition and the guides that cover therapy, school and money.